A common and useful type of container is the paperboard carton having a gabled top. Examples of such cartons include the everyday milk carton. In recent years, these cartons have been used for numerous other products, including foods, beverages and detergents. These cartons are typically coated or laminated with a heat-sealable plastic, which is used by manufactures to seal the cartons.
Typically, the contents of these cartons are dispensed by ripping open the gable top and unfolding a pourable spout. Once the carton is ripped open, it cannot be tightly resealed. To address this problem, cartons have been devised with reclosable spouts. These spouts are also referred to in the field has fitments, closures and caps. For convenience, they are referred to in this Application as simply "reclosable spouts".
A conventional spout is opened and closed by means of a removable cap, snap, hatch or the like. In the case of a capped spout, a person using the carton removes the cap to dispense the contents of the carton (typically a beverage). Because the carton has not been torn open, the contents can be tightly resealed.
Cartons having reclosable spouts are typically manufactured with automatic machinery (often referred to as "packaging machinery") which forms the carton from a flat piece (or "blank") of paperboard or other suitable material. After the carton has been partially formed (but not filled or sealed), the reclosable spout is attached. A typical spout consists of a plastic cylinder having a mounting flange at one end and a threaded, removable cap (or other conventional closure) at the other. The spout is mounted from inside the carton through a preformed hole formed in the paperboard blank so that the capped-end extends outward, while the flange is flush against the interior side of the carton wall. The flange is then ultrasonically welded to the wall of the carton. Examples of these types of containers and spouts are provided by U.S. Pat. No. 4,964,562, issued on Oct. 23, 1990 to Gordon, and U.S. Pat. No. 4,601,425, issued on Jul. 22, 1986 to Bachner.
The component of packaging machinery which attaches spouts to cartons is often referred to as an "applicator". Typically, applicators operate in two distinct steps. First, before the carton is filled and sealed, the applicator inserts the spout through the die cut hole. The applicator then moves the carton to a second station, where an anvil is placed inside the carton to firmly hold the spout's flange against the carton wall. An ultrasonic sealer located outside the carton then welds the flange to the carton.
While workable, these two-step applicators have a number of drawbacks. First, the use of more than one step is slower and less reliable. Ideally, a one-step applicator system would insert and weld the spout at the same time, thereby providing faster and more reliable operation. Second, prior to welding, the two-step applicator does not firmly hold the spout after insertion in the die cut hole. In some cases, the spout may shift position or even fall out. Ideally, the spout is subject to full mechanical control until it has been firmly welded. In this manner, the timing and positioning of the weld can be precisely controlled for better efficiency and quality.
In other kinds of applicators, the spout is placed in the ultrasonic sealer just prior to welding. The ultrasonic sealer then inserts the spout into the die cut hole just prior to welding. Because the ultrasonic sealer (by virtue of its size) is on the outside of the carton, this approach has the drawback of requiring that each spout's mounting flange must also be on the outside (as opposed to inside) of the carton. Flanges mounted on the outside of the carton are less desirable because they do not form as strong or reliable an attachment as flanges mounted on the inside. Moreover, the outside mounted flanges tend to be unsightly and make the carton less attractive to consumers. Additionally, when the flange is mounted on the outside, the contents of the carton are exposed to the raw paperboard edge forming the perimeter of the die cut hole. This exposure results in leakage or "wicking".
One problem common to all applicators is that they must be provided with a steady supply of spouts. Typically, a bulk supply of spouts is stored in a large bin placed on the factory floor. A bucket conveyor belt carries multiple loads of spouts to an elevated prefeeder or hopper. From the elevated hopper, the spouts are fed to an elevated centrifugal feeder. From the elevated centrifugal feeder, the spouts are delivered into the applicator by downwardly sloping gravity feed tracks.
While workable, this type of feeding system allows the spouts to bunch up along the gravity feed tracks. This bunching can cause the flanges of one spout to become jammed between the flange and cap of an adjacent spout, thereby preventing the feed mechanism from working properly. Ideally, a feed system would be avoid the necessity of having an elevated hopper or feeder, and would avoid above-described jamming problem.